Right and while some of these events may have happened regardless, I'm fully expecting there to be some sort of consequences. Some things may turn out better, others may become worse. The odds that he's going to keep Cyclops dead and Deadpool mute after DOFP when both he and the fans wish otherwise are pretty low. At the very least, Cyclops returning could be explained as Sinister cloning him. With Deadpool confirmed for X-Force and the second half of Origins taking place in 1979, it's easy to see some continuity wiped away.

Also, even without retcons, who's to say that Omega Red, Cameron Hodge, Apocalypse, Donald Pierce and Sinister wouldn't still be around? Regardless of what does or doesn't change, that's still five sequels.